DHT21 AM2301 Digital Temperature Humidity Sensor module

The DHT21 (also known as the AM2301) is a fully calibrated, long-range digital temperature and humidity sensor module widely used with microcontrollers like Arduino, ESP32, and Raspberry Pi. It incorporates a capacitive humidity sensing element and an NTC thermistor coupled to an internal 8-bit microcontroller to output precise digital environment readings.Core Technical SpecificationsThe DHT21 stands out for its high reliability and long-term stability. It operates on a standard single-bus digital data communication framework.

• Operating Voltage: 3.3V to 5.2V DC
• Humidity Measurement Range: 0% to 100% RH
• Humidity Precision: 3% RH (Maximum 5% RH)
• Temperature Measurement Range: -40C to +80C
• Temperature Precision: 0.5C
• Resolution: 0.1 for both parameters
• Sampling Period: 2 seconds average between readings

Wiring and Pinout ConfigurationUnlike basic unhoused components, the DHT21 AM2301 is heavily utilized for commercial and harsh field deployments because it usually comes enclosed in a protective plastic shell with pre-soldered extension wires. It uses three primary wires:

• Red Wire (VCC): Connects to the power supply (3.3V or 5V).
• Black Wire (GND): Connects to system Ground.
• Yellow Wire (SDA / Data): Connects to any digital I/O pin on your micro-controller.

Note: The DHT21 features an integrated pull-up resistor on the data line.